I posted here about a problem I had with buzzing in my home. Cant find the post so I will explain.
Problem was the contacts on certain breakers in the panel were worn/loose. Old panel. Caused sparks under current draw. Replaced them with new breakers and that problem is now gone. Next, found one circuit had induced voltage on it with the breaker disconnected. (Physical run of the wires, not dangerous, no current.) Not sure if this is a problem regarding noise. And last, I used a extension power bar with surge suppression. It caused my pedalboard and amps to pop (audio) when switched. Using a simple power bar got rid of the pops. Your electrician should find the cause / solution.